Controlled drug-eluting stents polymers

Polymers—the optimal system for controlled drug-eluting stents... 

J.S.W. Kwong, and C.-M. Yu, Clinical outcomes of biodegradable polymer drug-eluting stents for percutaneous coronary intervention An updated meta-analysis of randomized controlled trials, Clin. Cardiol, 37 (7), 440-453,2014. 

Overall, key takeaways from the nonpoly meric paclitaxel delivery studies were that despite their improvement of angiographic parameters, paclitaxel-eluting stents without a polymer carrier did not demonstrate a positive effect on clinical outcomes, as seen with polymer-based paclitaxel elution (65), discussed in the next section. Potential reasons for the failure of such an approach could be loss of drug to the systemic circulation prior to reaching the target site during the stent deployment procedure, variability associated with the dose delivered to the lesion, and lack of control over drug-release kinetics due to the absence of a polymer carrier. 

Resolute Integrity (Medtronic, Minneapolis, MN) is a 2012 PDA approved stent, that uses zotarolimus (160 g/cm ) that is 85% eluted in the first 2 months, blended with Biolinx polymer coated on a cobalt-chromium 91 micron strut. Despite its similarity with Endeavour, it was redesigned to have higher biocompatibility and controlled drug release. It was shown that Resolute had comparable results with everolimus eluting stents in the RESOLUTE All-comers trial [75-77], with other trials such as the TWENTE trial having comparable results [78]. Albeit Resolute is the only DES to be indicated specifically for diabetic patients, data from EXCELLENT and RESOLUTE-Korea show that the same could go for everolimus eluting stents [79]. 

Finally, we have the Bioabsorbable therapeutics stent (Bioreabsorbable Therapeutics Inc., Menlo Park, CA), a sirolimus-eluting FBS composed of salicylic acid. It is also coated with a polymer layer responsible for controlled release of the drugs (Figure 5D). The coating is made up of repeated salicylic acid molecules... 

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